CN215870902U

CN215870902U - Lithium battery power supply system with linear dynamic charging current-limiting function for communication equipment

Info

Publication number: CN215870902U
Application number: CN202122101547.9U
Authority: CN
Inventors: 韩锋; 姚继忠; 龚华刚; 潘佩
Original assignee: Shanghai Huijue Network Communication Equipment Co ltd
Current assignee: Shanghai Huijue Network Communication Equipment Co ltd
Priority date: 2021-09-01
Filing date: 2021-09-01
Publication date: 2022-02-18
Anticipated expiration: 2031-09-01

Abstract

The utility model discloses a lithium battery power supply system with a linear dynamic charging current-limiting function for communication equipment, which comprises an alternating current power distribution unit, a rectifying unit and a direct current power distribution unit, wherein the direct current power distribution unit comprises an equipment load power supply module and a standby battery module which are connected in parallel; the total equipment load current of the system is collected in real time, the charging current of the standby battery module is limited according to the load current, the charging current of the standby battery module in the system is regulated and controlled linearly in real time, the system can not automatically stop and protect equipment due to the fact that the charging current of the standby battery module is too large, and the operation reliability and the stability of the whole equipment are improved.

Description

Lithium battery power supply system with linear dynamic charging current-limiting function for communication equipment

Technical Field

The utility model relates to the technical field of communication equipment, in particular to a lithium battery power supply system with a linear dynamic charging current-limiting function for communication equipment.

Background

The basic power system for communication is indispensable key equipment of a communication system, stable, continuous, safe and reliable power supply is a basic requirement of communication power supply design, and battery energy storage and power backup are necessary links of modern communication power supplies. For an important communication system, the storage battery can prolong the working time of the communication equipment, so that the system can still provide communication service in the state of mains supply power failure, and the communication equipment adopts a direct current basic power supply and just uses the storage battery to realize power backup. Based on the continuous reduction of the manufacturing cost of lithium ion batteries and other advantages, lithium batteries, especially lithium iron phosphate batteries, have been widely used in the field of communication power supplies, and currently, new communication systems, especially 5G communication power supply systems, all use large-capacity lithium iron phosphate battery packs as energy storage devices, while lead-acid batteries used in original systems are being successively replaced by lithium iron phosphate batteries, and compared with lead-acid batteries, lithium batteries have the characteristics of large power density and large charging and discharging currents, which can reach 1-1.5C charging currents, while lead-acid batteries are only 0.1-0.3C, and because lithium batteries have large charging currents, they have new problems when applied to communication power supply systems.

In general, the design capacity of a communication power supply system is designed according to the load power and the charging power of a backup battery, and the charging power of a lead-acid battery can be set to 0.1C to 0.2C. For example, for a nominally 48V/100A embedded power system, a 100Ah lead-acid battery can be configured, and its actual load capacity is 80A (minus 20A on the basis of 100A), that is, in the limit of loss of the lead-acid battery, a load current exceeding 80A may cause the rectified power to overload for protection, and the system generally performs deep current-limiting protection until overload shutdown. In the same 48V/100A power supply system, if a 100Ah lithium iron phosphate battery is provided, the loading capacity can be zero under the limit condition that the battery is charged due to power shortage. As shown in FIG. 7, FIG. 7 is a system diagram of a 48V/50Ah, 48V/100Ah lithium iron phosphate battery in a conventional design, in which a battery management system BMS is arranged in a dotted line. It is apparent from the figure that the battery does not have a linear charge/discharge current control function, and the charge/discharge current of the battery can be controlled only by high-speed chopping, and the peak current cannot be limited.

Therefore, a strange phenomenon occurs in the currently used lithium iron phosphate battery communication power supply system, namely, the communication power supply system with the lithium iron phosphate battery for power backup works at full load, when an alternating current power supply is suddenly powered off, the lithium battery can discharge power to supply power to a load until the voltage of the battery is close to an undervoltage protection point. When the commercial power returns to normal, the rectifier starts to work to directly supply power to the load under normal conditions, and meanwhile, the lithium battery pack is charged. However, due to the serious power shortage of the lithium battery, the charging current is large, the sum of the load current and the charging current far exceeds the load capacity of the rectifier, the rectifier is overloaded and is subjected to shutdown protection, and at the moment, the communication system is in a state that the mains supply is normal and the equipment is in a power-off state, namely, the power is supplied but the power cannot be supplied.

The above strange phenomena occur mainly due to the following two reasons: firstly, the power supply capacity is unreasonable in configuration, the capacity of the rectifier is the sum of the maximum charging current and the maximum load current, and redundancy is reserved; secondly, the charging current of the lithium battery is not limited. If the rectification power of the rectifier is increased, the cost of other electric parts of the system except the battery is doubled, in addition, the BMS of the existing lithium iron phosphate battery for communication does not have a linear control function on the charging current, only an electronic switch is used for carrying out simple on-off control, although the rectification power supply can limit the charging power by reducing the voltage, if the voltage is reduced to an undervoltage protection point and still needs to be reduced continuously, the system can be shut down for protection, and therefore no matter how the charging current limit point is set, the system can not supply power under the condition. For example, when the system limits the charging current by adjusting the charging voltage, the rectifier is turned off by the protection circuit when the limited charging voltage is lower than the protection value (generally 43.5V), and the battery has no discharge at this time, so the system has an ac power supply but no dc power output.

Two solutions to this problem exist, namely, increasing the configuration capacity of the power supply system. For example, a load of 48V/100A is directly matched with a power supply system of 200A. The scheme directly provides larger charging power, solves the problem of overlarge charging current of the lithium battery to a certain extent, but inevitably has resource waste to a large extent and needs sufficient funds. And the other is to adopt a lithium battery PACK with a DC/DC converter. The bidirectional DC/DC converter is directly added into the lithium battery PACK, so that the charge and discharge of the battery can be directly and linearly regulated, the stability of the system is ensured, but the cost of the battery system is obviously improved, the power supply system provided with the common lithium battery or the lead-acid battery cannot be helped, and the two batteries cannot be used in a mixed manner.

SUMMERY OF THE UTILITY MODEL

The utility model aims to solve the technical problem of providing a lithium battery power supply system with a linear dynamic charging current limiting function for communication equipment, which can linearly regulate and control charging current in real time, avoid the phenomenon of shutdown protection caused by overlarge charging current of a lithium battery, simultaneously keep output voltage in a stable working range of load equipment and finally improve reliability and stability.

In order to solve the technical problems, the technical scheme of the utility model is as follows: the lithium battery power supply system with the linear dynamic charging current-limiting function for the communication equipment comprises an alternating current power distribution unit connected with a mains supply, wherein the output end of the alternating current power distribution unit is electrically connected with a rectifying unit, the output end of the rectifying unit is electrically connected with a direct current power distribution unit, the direct current power distribution unit comprises an equipment load power supply module and a standby battery module which are connected with the output end of the rectifying unit in parallel, the input end of the equipment load power supply module is connected with a load current acquisition unit in series, the input end of the standby battery module is connected with a dynamic charging limiting unit in series, the load current acquisition unit and the dynamic charging limiting unit are arranged behind the parallel shunting point of the equipment load power supply module and the standby battery module, and the load current acquisition unit is electrically connected with the dynamic charging limiting unit and further comprises a monitoring unit, the alternating current distribution unit, the rectifying unit, the direct current distribution unit and the dynamic charging limiting unit are respectively connected to the monitoring unit.

As a preferred technical solution, the backup battery module at least includes two backup lithium battery packs, and each of the backup lithium battery packs is connected in parallel to an output end of the dynamic charge limiting unit.

As a preferred technical solution, the output end of the dynamic charge limiting unit is connected in series with a battery load disconnection breaker, the battery load disconnection breaker is arranged in front of a parallel shunt point of each of the lithium battery packs, and each of the lithium battery packs is respectively connected in series with a normally open contact of the disconnection breaker.

As a preferred technical scheme, the backup battery module at least includes two backup lithium battery packs, each backup lithium battery pack is respectively and correspondingly connected in series with the dynamic charge limiting unit, and the load current collecting unit is respectively connected to each dynamic charge limiting unit.

As a preferable technical solution, the dynamic charge limiting unit includes an input filter capacitor C1, a control chip U1, and an output filter capacitor C2, which are connected in parallel in sequence to the output end of the rectifying unit, the control chip U1 is provided with a control signal end, a voltage input end, a load current collecting end, an input current collecting end, an output current collecting end, two sets of driving ends, and an output voltage collecting end, the control signal end is connected to the monitoring unit, the voltage input end is correspondingly connected to the positive electrode and the negative electrode of the rectifying unit, the load current collecting end is electrically connected to the load current collecting unit, the input current collecting end is connected to the negative electrode of the rectifying unit through the input current collecting unit, the output current collecting end is connected to the negative electrode of the rectifying unit through the output current collecting unit, one set of the driving ends is connected to the gate and the source of the field effect transistor Q1, the source electrode of the field effect transistor Q1 is further connected in series with the input current acquisition unit, the drain electrode of the field effect transistor Q1 is connected in series with the output current acquisition unit through an energy storage inductor L1, the other group of the drive end is connected to the grid electrode and the source electrode of the field effect transistor Q2, the source electrode of the field effect transistor Q2 is further connected to the energy storage inductor L1 through a resistor RS1, the drain electrode of the field effect transistor Q2 is connected to the anode of the rectification unit, the output voltage acquisition end is connected to the cathode of the output end filter capacitor C2, and the cathode of the output end filter capacitor C2 is arranged between the energy storage inductor L1 and the output current acquisition unit.

As a preferable technical solution, another two groups of driving terminals are further added to the control chip U1, one group of driving terminals is connected to the gate and the source of the field effect transistor Q3, the drain of the field effect transistor Q3 is connected to the anode of the rectifying unit, the source of the field effect transistor Q3 is connected to the output end of the energy storage inductor L1 through a resistor RS2, the other group of driving terminals is connected to the gate and the source of the field effect transistor Q4, and the source and the drain of the field effect transistor Q4 are connected between the energy storage inductor L1 and the output end filter capacitor C2.

As a preferred technical scheme, the load current collecting unit, the input current collecting unit and the output current collecting unit are respectively set as hall direct current sensors.

As an improvement to the above technical solution, the dynamic charge limiting unit includes an input filter capacitor C1, a control chip U1, a fast recovery diode D1, and an output filter capacitor C2, which are connected in parallel to the output end of the rectifying unit in sequence, the control chip U1 is provided with a control signal end, a voltage input end, a load current collecting end, an input current collecting end, an output current collecting end, a group of driving ends, and an output voltage collecting end, the control signal end is connected to the monitoring unit, the voltage input end is correspondingly connected to the positive and negative electrodes of the rectifying unit, the load current collecting end is electrically connected to the load current collecting unit, the input current collecting end is connected to the negative electrode of the rectifying unit through the input current collecting unit, and the output current collecting end is connected to the negative electrode of the rectifying unit through the output current collecting unit, the driving end is connected to a grid and a source of a field effect transistor Q1, the source of the field effect transistor Q1 is further connected in series with the input current acquisition unit, the drain of the field effect transistor Q1 is connected in series with the output current acquisition unit through an energy storage inductor L1, the energy storage inductor L1 is arranged between the fast recovery diode D1 and the output end filter capacitor C2, and the negative electrode of the output end filter capacitor C2 is arranged between the energy storage inductor L1 and the output current acquisition unit.

By adopting the technical scheme, the lithium battery power supply system with the linear dynamic charging current-limiting function for the communication equipment comprises an alternating current power distribution unit connected with a mains supply, the output end of the alternating current power distribution unit is electrically connected with a rectifying unit, the output end of the rectifying unit is electrically connected with a direct current power distribution unit, the direct current power distribution unit comprises an equipment load power supply module and a standby battery module which are connected in parallel with the output end of the rectifying unit, the input end of the equipment load power supply module is connected with a load current acquisition unit in series, the input end of the standby battery module is connected with a dynamic charging limiting unit in series, the load current acquisition unit and the dynamic charging limiting unit are both arranged behind the parallel shunting point of the equipment load power supply module and the standby battery module, and the load current acquisition unit is electrically connected with the dynamic charging limiting unit, the alternating current power distribution unit, the rectifying unit, the direct current power distribution unit and the dynamic charging limiting unit are respectively connected to the monitoring unit; the utility model has the following beneficial effects: through carrying out simple transformation to original system, can the total equipment load current of real-time acquisition system, come to restrict the charging current of being equipped with electric battery module according to the size of the load current who gathers again, realize the charging current of being equipped with electric battery module among the real-time linear regulation and control system, make the system can not take place again because the charging current of being equipped with electric battery module is too big and lead to equipment automatic shutdown protection, still enable output voltage to keep in load equipment's stable working range simultaneously, make the operational reliability of whole equipment, stability all obtain improving, the expansion of the actual load capacity of system has also been realized.

Drawings

The drawings are only for purposes of illustrating and explaining the present invention and are not to be construed as limiting the scope of the present invention. Wherein:

FIG. 1 is a simplified schematic diagram of a 48V DC base power system according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of a simplified circuit for sharing a dynamic charge limiting device with each battery according to an embodiment of the present invention;

FIG. 3 is a schematic circuit diagram of a dynamic charge limiting unit according to an embodiment of the present invention;

FIG. 4 is a schematic diagram of a simple circuit in which each battery is individually matched with a dynamic charge limiting device according to a second embodiment of the present invention;

FIG. 5 is a schematic circuit diagram of a dynamic charge limiting unit according to a second embodiment of the present invention;

FIG. 6 is a schematic circuit diagram of a dynamic charge limiting unit according to a third embodiment of the present invention;

fig. 7 is a block diagram illustrating a structure of a lithium iron phosphate battery pack according to the related art.

Detailed Description

The utility model is further illustrated below with reference to the figures and examples. In the following detailed description, certain exemplary embodiments of the present invention are described by way of illustration only. Needless to say, a person skilled in the art realizes that the described embodiments can be modified in various different ways without departing from the spirit and scope of the present invention. Accordingly, the drawings and description are illustrative in nature and not intended to limit the scope of the claims.

The first embodiment is as follows:

as shown in fig. 1 and 2, the lithium battery power supply system with the linear dynamic charging current-limiting function for the communication device is used in the communication device, and specifically includes an ac power distribution unit connected with a mains supply, an output end of the ac power distribution unit is electrically connected with a rectification unit, and an output end of the rectification unit is electrically connected with a dc power distribution unit. a-48V dc base power supply is generally used in communication equipment, and the working process of the power supply system is as follows: the alternating current commercial power of 220V or 380V is firstly led into the equipment through the alternating current distribution unit, and then is rectified by the rectifying unit to convert the commercial power voltage into direct current of-48V. The alternating current distribution unit comprises devices such as a circuit breaker and a lightning protection module. The rectifying unit comprises an AC/DC rectifier, a direct current lightning protection module and the like and consists of a plurality of high-frequency switch rectifying circuits, the output sides of the rectifiers are mutually connected in parallel, the negative end of each rectifier is connected to a-48V direct current bus bar, and the positive end of each rectifier is grounded.

The direct current distribution unit comprises an equipment load power supply module and a standby battery module which are connected to the output end of the rectification unit in parallel, and the-48V direct current obtained through conversion is used for starting the equipment load power supply module in the equipment and charging the standby battery module. Wherein the device load power supply module comprises an LLVD load and a BLVD load. The LLVD load is a one-time power-off load, when the mains supply stops supplying power, the load can be supplied with power by the standby battery module, and when the electric quantity of the standby battery module is reduced to a certain degree, the power supply to the standby battery module can be stopped firstly; the BLVD load is a secondary power-off load, and when the commercial power stops supplying power, the standby battery module continues supplying power until the electric quantity of the standby battery module is discharged. When the commercial power resumes to supply power, can pass through the rectifier unit is right the battery module that is equipped with power charges to the use of having a power failure next time of being equipped with, simultaneously the rectifier unit also can be right equipment load power module supplies power. The direct current distribution unit is also provided with a direct current contactor, a circuit breaker (or a fuse), a copper bar and other conventional structures, which are not described in detail herein.

The input of equipment load power module has concatenated load current acquisition unit, the input of being equipped with electric battery module has concatenated dynamic charging restriction unit, just load current acquisition unit dynamic charging restriction unit all locates equipment load power module with be equipped with after electric battery module's parallelly connected shunting point, load current acquisition unit electricity is connected to dynamic charging restriction unit still includes the monitoring unit, the alternating current distribution unit the rectifier unit direct current distribution unit with dynamic charging restriction unit is connected to respectively the monitoring unit. The monitoring unit comprises a microprocessor, an LCD display, a communication interface (RS485, CAN, LAN), an I/O signal processing circuit, a signal driving and amplifying circuit and the like, and is used for acquiring and monitoring the working state of each module in real time and realizing the operation control of the whole system.

As shown in fig. 2, the battery backup module at least includes two battery backup sets, each of the battery backup sets is connected in parallel to the output end of the dynamic charge limiting unit, and the battery backup sets are configured as a lithium iron phosphate battery set. The output end of the dynamic charging limiting unit is connected with a battery load disconnection circuit breaker in series, the battery load disconnection circuit breaker is arranged in front of a parallel shunting point of each standby lithium battery pack, and each standby lithium battery pack is correspondingly connected with a normally open contact of the disconnection circuit breaker in series. The current signal of the load current acquisition unit is acquired by the dynamic charge limiting unit and is used as a feedback signal source for dynamic current control, and the charging current of the standby battery module is reduced when the load current of the equipment load power supply module is larger by utilizing the objective fact that the communication load current continuously changes along with time; when the load current of the equipment load power supply module is small, the charging current of the standby battery module is increased, so that the charging current of the standby battery module is increased as much as possible on the premise of ensuring the normal power supply of the whole system.

As shown in fig. 3, the dynamic charge limiting unit includes an input filter capacitor C1, a control chip U1 and an output filter capacitor C2, which are connected in parallel in sequence to the output end of the rectifying unit, the control chip U1 is provided with a control signal end, a voltage input end Vin, a load current collecting end Iload, an input current collecting end Iin, an output current collecting end Iout, two sets of driving ends and an output voltage collecting end Vout, the control signal end is connected to the monitoring unit, the voltage input end Vin is correspondingly connected to the positive and negative electrodes of the rectifying unit, the load current collecting end Iload is electrically connected to the load current collecting unit, the input current collecting end Iin is connected to the negative electrode of the rectifying unit through the input current collecting unit, the output current collecting end Iout is connected to the negative electrode of the rectifying unit through the output current collecting unit, one set of the driving ends is connected to the gate (G) and the source (S) of the field effect transistor Q1, the source (S) of the field effect transistor Q1 is also connected in series with the input current collecting unit, the drain (D) of the field effect transistor Q1 is connected in series with the output current collecting unit through an energy storage inductor L1, the other group of driving terminals are connected to the gate (G) and the source (S) of the field effect transistor Q2, the source (S) of the field effect transistor Q2 is also connected to the energy storage inductor L1 through a resistor RS1, the drain (D) of the field effect transistor Q2 is connected to the anode of the rectifying unit, the output voltage collecting terminal Vout is connected to the cathode of the output terminal filter capacitor C2, the cathode of the output terminal filter capacitor C2 is arranged between the energy storage inductor L1 and the output current collecting unit, and the load current collecting unit, the input current collecting unit and the output current collecting unit are respectively set as Hall direct current sensors, the load current acquisition unit is a Hall direct current sensor H3, the input current acquisition unit is a Hall direct current sensor H1, and the output current acquisition unit is a Hall direct current sensor H2.

The dynamic charge limiting unit of the embodiment adopts a negative input Buck conversion circuit, a DC voltage of-48V (actually, any voltage of-40V to-60V) is applied to the input end of the circuit, the filter capacitor C1 at the input end is an electrolytic capacitor, the filter capacitor C1 at the input end plays a role in filtering, not only can the input ripple be filtered, but also the reverse-injection ripple current of the unit can be inhibited, and the positive end of the filter capacitor C1 is connected with the 0V end of the input and output. The Hall direct current sensor H1 collects input current and is connected in series between the input negative terminal and the source (S) of the field effect transistor Q1. The hall direct current sensor H2 collects an output current, i.e., a charging current of the backup battery module, and is connected in series between the energy storage inductor L1 and the output negative terminal. The field effect transistor Q1 and the field effect transistor Q2 are both high-power field effect transistors MOSFET, the field effect transistor Q1 is responsible for circuit chopping, direct-current voltage is converted into high-frequency pulses through high-frequency switching action, the drain electrode (D) of the field effect transistor Q1 is connected with the other ends of the resistor RS1 and the energy storage inductor L1, the driving mode of the field effect transistor Q2 is complementary to that of the field effect transistor Q1, namely the field effect transistor Q1 and the field effect transistor Q2 are alternately conducted, and the field effect transistor Q2 is used for enabling the energy storage inductor L1 to follow current when the field effect transistor Q1 is turned off, so that the energy storage of the energy storage inductor L1 is released to the output; the resistor RS1 is a milliohm resistor and is used for sampling the overcurrent protection of the field effect transistor Q2, and the other end of the resistor RS1 is connected with the source (S) of the field effect transistor Q2; the output end filter capacitor C2 is an electrolytic capacitor, plays a role in filtering, is mainly used for filtering high-frequency switch ripples, and has a positive end connected with an output 0V end and a negative end connected with the energy storage inductor L1 and the Hall direct current sensor H2; the control chip U1 generates PWM signals through collecting input current, output current, load current and input voltage of the equipment load power supply module and battery voltage, chops the voltage of-48V through high-frequency switching on and off of the field-effect tube Q1 and the field-effect tube Q2, and controls the output current after filtering through the energy storage inductor L1 and the output end filter capacitor C2, namely controls the charging current of each spare battery pack. The control chip U1 can communicate with the monitoring unit through a digital communication port and receive control thereof.

When the mains supply is normal, the system is powered by the rectifying unit, the load current of the equipment load power supply module is collected by the Hall direct current sensor H3 and then is transmitted to the Buck conversion circuit, and the charging current of the lithium battery pack is determined in real time according to the total capacity of the system; when the commercial power is disconnected, the dynamic charging limiting unit stops charging and limiting current, the discharging current of the standby lithium battery pack is discharged through the 0V bus to the field effect transistor Q1 and the energy storage inductor L1 to supply power to the equipment load power supply module, at the moment, the field effect transistor Q1 can be completely conducted to reduce the reverse conduction voltage drop of the diode and reduce the loss, and a Boost circuit can be formed by the field effect transistor Q2, the energy storage inductor L1 and the input end filter capacitor C1 to reversely Boost the battery voltage to a proper level and output the battery voltage to a-48V bus to Boost the voltage of a direct current system. Therefore, the circuit shown in fig. 3 has a bidirectional control mode, which helps to keep the-48V bus voltage stable, and the circuit is used as a Buck circuit with synchronous rectification, and actually also forms a Buck-Boost bidirectional DC/DC conversion circuit.

Example two:

as shown in fig. 4, the embodiment is different from the implementation benefits in that the standby battery module at least includes two standby lithium battery packs, each of the standby lithium battery packs is respectively and correspondingly connected with the dynamic charge limiting unit in series, and the load current collecting unit is respectively connected to each of the dynamic charge limiting units. The capacity of the dynamic charge limiting unit in this embodiment can be set to be smaller, and the standby lithium battery packs with different SOCs can be used separately, which is beneficial to fully exerting the energy storage efficiency of the lithium battery, but the cost of this scheme is slightly higher than that of the embodiment.

As shown in fig. 5, in the dynamic charge limiting unit of this embodiment, on the basis of the first embodiment, two additional sets of driving terminals are added to the control chip U1, one of the driving terminals is connected to the gate (G) and the source (S) of the fet Q3, the drain (D) of the fet Q3 is connected to the positive electrode of the rectifying unit, the source (S) of the fet Q3 is connected to the output terminal of the energy storage inductor L1 through a resistor RS2, the other driving terminal is connected to the gate (G) and the source (S) of the fet Q4, and the source (S) and the drain (D) of the fet Q4 are connected between the energy storage inductor L1 and the output terminal filter capacitor C2.

By additionally arranging the field effect transistor Q3, the functions of the field effect transistor Q3 are changed from unidirectional voltage reduction and reverse voltage increase into bidirectional voltage increase and reduction, and the functions are doubled. The resistor Rs2 is used for overload protection sampling of the fet Q3, but the cost is slightly increased.

Example three:

as shown in fig. 6, the difference between this embodiment and the first embodiment is that the circuit structure of the dynamic charge limiting unit is slightly adjusted, that is, the dynamic charge limiting unit includes an input filter capacitor C1, a control chip U1, a fast recovery diode D1 and an output filter capacitor C2, which are connected in parallel to the output end of the rectifying unit in sequence, the control chip U1 is provided with a control signal end, a voltage input end Vin, a load current collecting end Iload, an input current collecting end Iin, an output current collecting end Iout, a group of driving ends and an output voltage collecting end Vout, the control signal end is connected to the monitoring unit, the voltage input end Vin is correspondingly connected to the positive and negative electrodes of the rectifying unit, the load current collecting end Iload is electrically connected to the load current collecting unit, the input current collecting end Iin is connected to the negative electrode of the rectifying unit through the input current collecting unit, the output current acquisition end Iout is connected to the negative pole of the rectification unit through an output current acquisition unit, the driving end is connected to a grid (G) and a source (S) of a field effect transistor Q1, the source (S) of the field effect transistor Q1 is connected with the input current acquisition unit in series, a drain (D) of the field effect transistor Q1 is connected with the output current acquisition unit in series through an energy storage inductor L1, the energy storage inductor L1 is arranged between the fast recovery diode D1 and the output end filter capacitor C2, and the negative pole of the output end filter capacitor C2 is arranged between the energy storage inductor L1 and the output current acquisition unit. The load current acquisition unit, the input current acquisition unit and the output current acquisition unit are respectively set as Hall direct current sensors, the load current acquisition unit is a Hall direct current sensor H3, the input current acquisition unit is a Hall direct current sensor H1, and the output current acquisition unit is a Hall direct current sensor H2.

In the embodiment, the fast recovery diode D1 is used to replace the fet Q2, so that the circuit has only a one-way voltage reduction function, and after the rectifier module is powered off, the lithium battery pack can be powered back and forth, and at this time, the fet Q1 can be continuously turned on to reduce the loss of the diode. Because the circuit does not have the synchronous rectification function, the power consumption is larger, the voltage of the lithium battery pack with the battery and the voltage stability of a-48V bus cannot be improved, but the implementation cost is slightly low.

In the embodiments of the present invention, a current divider and a corresponding current signal amplifying circuit can be used to replace the hall dc current sensor H3, so that the relative cost is reduced, but the matching problem of signal levels needs to be dealt with, and the complexity is increased.

The utility model determines the charging current value of the standby lithium battery pack by measuring the total load current of the direct current power supply system and the total capacity dynamic of the system, and dynamically limits the charging current of the standby lithium battery pack by adopting a linear dynamic charging limiting unit, so that the total rectified power of the system does not exceed the design capacity, the continuity of the direct current power supply of the system can be ensured, and the practical operation characteristics that the size of the communication load changes along with the number of the accessed users at any time can be utilized, so that the standby lithium battery pack is charged by large current when the load of the system is light, and charged by small current when the load is heavy, and the uninterrupted power supply of the direct current load is always ensured. The dynamic charging limiting unit can be used in brand-new communication equipment and can also be used for modifying stock equipment, the technical complexity of the dynamic charging limiting unit is far lower than that of rectifying equipment, the cost of the dynamic charging limiting unit is far lower than that of system capacity expansion, and the modification difficulty of the existing equipment is lower. Due to the linear dynamic charging current limiting function, the system can detect the current of the load in real time, adjust the charging current of the standby lithium battery pack in real time, and make full use of the difference of the communication load in different time periods to maximize the charging current. The most direct advantage that the utility model can produce lies in, while not increasing the communication power system redundancy, can drive the larger communication equipment load, save the investment cost of the apparatus, because the system will work in the high load state for more time intervals at the same time, make the system have higher energy efficiency ratio after improving, help energy-conservation and environment-friendly.

The description of the present invention has been presented for purposes of illustration and description, and is not intended to be exhaustive or limited to the utility model in the form disclosed. Many modifications and variations will be apparent to practitioners skilled in this art. The embodiment was chosen and described in order to best explain the principles of the utility model and the practical application, and to enable others of ordinary skill in the art to understand the utility model for various embodiments with various modifications as are suited to the particular use contemplated.

Claims

1. Take linear dynamic charging current limiting function's lithium cell electrical power generating system for communication equipment, include the alternating current distribution unit of being connected with mains supply, the output electricity of alternating current distribution unit is connected with the rectification unit, the output electricity of rectification unit is connected with the direct current distribution unit, the direct current distribution unit including parallel connection in the equipment load power module and the battery module that is equipped with of rectification unit output, its characterized in that: the input of equipment load power module has concatenated load current acquisition unit, the input of being equipped with electric battery module has concatenated dynamic charging restriction unit, just load current acquisition unit dynamic charging restriction unit all locates equipment load power module with be equipped with after electric battery module's parallelly connected shunting point, load current acquisition unit electricity is connected to dynamic charging restriction unit still includes the monitoring unit, the alternating current distribution unit the rectifier unit direct current distribution unit with dynamic charging restriction unit is connected to respectively the monitoring unit.

2. The lithium battery power supply system with the linear dynamic charging current limiting function for the communication device according to claim 1, wherein: the standby battery module at least comprises two standby lithium battery packs, and each standby lithium battery pack is connected to the output end of the dynamic charging limiting unit in parallel.

3. The lithium battery power supply system with the linear dynamic charging current limiting function for the communication device according to claim 2, wherein: the output end of the dynamic charging limiting unit is connected with a battery load disconnection circuit breaker in series, the battery load disconnection circuit breaker is arranged in front of a parallel shunting point of each standby lithium battery pack, and each standby lithium battery pack is correspondingly connected with a normally open contact of the disconnection circuit breaker in series.

4. The lithium battery power supply system with the linear dynamic charging current limiting function for the communication device according to claim 1, wherein: the standby battery module at least comprises two standby lithium battery packs, each of the standby lithium battery packs is correspondingly connected with the dynamic charging limiting unit in series, and the load current acquisition unit is connected to each of the dynamic charging limiting units.

5. The lithium battery power supply system with the linear dynamic charging current limiting function for the communication device according to claim 2 or 4, wherein: the dynamic charging limiting unit comprises an input end filter capacitor C1, a control chip U1 and an output end filter capacitor C2 which are sequentially connected in parallel with the output end of the rectifying unit, the control chip U1 is provided with a control signal end, a voltage input end, a load current collecting end, an input current collecting end, an output current collecting end, two groups of driving ends and an output voltage collecting end, the control signal end is connected to the monitoring unit, the voltage input end is correspondingly connected to the positive electrode and the negative electrode of the rectifying unit, the load current collecting end is electrically connected to the load current collecting unit, the input current collecting end is connected to the negative electrode of the rectifying unit through the input current collecting unit, the output current collecting end is connected to the negative electrode of the rectifying unit through the output current collecting unit, one group of the driving ends is connected to the grid electrode and the source electrode of the field effect transistor Q1, the source electrode of the field effect transistor Q1 is further connected in series with the input current acquisition unit, the drain electrode of the field effect transistor Q1 is connected in series with the output current acquisition unit through an energy storage inductor L1, the other group of the drive end is connected to the grid electrode and the source electrode of the field effect transistor Q2, the source electrode of the field effect transistor Q2 is further connected to the energy storage inductor L1 through a resistor RS1, the drain electrode of the field effect transistor Q2 is connected to the anode of the rectification unit, the output voltage acquisition end is connected to the cathode of the output end filter capacitor C2, and the cathode of the output end filter capacitor C2 is arranged between the energy storage inductor L1 and the output current acquisition unit.

6. The lithium battery power supply system with the linear dynamic charging current limiting function for the communication device according to claim 5, wherein: the control chip U1 is further provided with two other groups of driving ends, one group of driving ends is connected to the gate and the source of a field effect transistor Q3, the drain of the field effect transistor Q3 is connected to the anode of the rectifying unit, the source of the field effect transistor Q3 is connected to the output end of the energy storage inductor L1 through a resistor RS2, the other group of driving ends is connected to the gate and the source of a field effect transistor Q4, and the source and the drain of the field effect transistor Q4 are connected between the energy storage inductor L1 and the output end filter capacitor C2.

7. The lithium battery power supply system with the linear dynamic charging current limiting function for the communication device according to claim 5, wherein: the load current acquisition unit, the input current acquisition unit and the output current acquisition unit are respectively set as Hall direct current sensors.

8. The lithium battery power supply system with the linear dynamic charging current limiting function for the communication device according to claim 2 or 4, wherein: the dynamic charging limiting unit comprises an input end filter capacitor C1, a control chip U1, a fast recovery diode D1 and an output end filter capacitor C2 which are sequentially connected in parallel with the output end of the rectifying unit, the control chip U1 is provided with a control signal end, a voltage input end, a load current acquisition end, an input current acquisition end, an output current acquisition end, a group of driving ends and an output voltage acquisition end, the control signal end is connected to the monitoring unit, the voltage input end is correspondingly connected to the positive electrode and the negative electrode of the rectifying unit, the load current acquisition end is electrically connected to the load current acquisition unit, the input current acquisition end is connected to the negative electrode of the rectifying unit through the input current acquisition unit, the output current acquisition end is connected to the negative electrode of the rectifying unit through the output current acquisition unit, and the driving ends are connected to the grid electrode and the source electrode of the field effect transistor Q1, the source electrode of field effect transistor Q1 still with the input current acquisition unit concatenates the setting, the drain electrode of field effect transistor Q1 pass through energy storage inductance L1 with the output current acquisition unit concatenates the setting, energy storage inductance L1 is located fast recovery diode D1 with between output filter capacitor C2, output filter capacitor C2's negative pole is located energy storage inductance L1 with between the output current acquisition unit.